Originally Posted By: mdonohue05
Maybe you are struggling with a fuel issue. My 261 runs a pair of weber 38mm carbs on a Clifford manifold. This set up was new to me last year. I previously ran 32/36 weber pinto carbs. Did not have a problem when I ran the motor up. 5/16 lines. When I ran the 57 at last year's trifive nationals, ran the carbs out of fuel every run. The video is my first run with the new set up.

You can hear the miss and popping as I pulled into second gear. Is this what yours sounds like? Even though this motor is not making all that much power, probably 200 or less, I still ran it out of fuel with the mechanical pump and 5/16 lines. So maybe you start there and upgrade the lines, pickup and pump, install an electric pump like a carter 4070 and eliminate the fuel supply as an issue.

www.youtube.com/watch?v=1xJbck9QQH8


Thanks mdonohue05 - great insight and interesting that the mechanical pump and 5/16" lines didn't have enough on your new pair of Webers.
That's a great looking '57 and look at that 261 spin those tires - very cool and thank you for sharing that.
I think the biggest thing for increasing delivery would be increasing the size of the pickup tube out of the tank - it's 5/16".